/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package com.sea.ftp.command.impl.listing;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import com.sea.ftp.exception.FTPServerException;
import com.sea.ftp.ftplet.FileSystemView;
import com.sea.ftp.ftplet.FtpFile;

/**
 * <strong>Internal class, do not use directly.</strong>
 * 
 * This class prints file listing.
 *
 * @author <a href="http://mina.apache.org">Apache MINA Project</a>
 */
public class DirectoryLister {

	private String traverseFiles(final List<FtpFile> files,
			final FileFilter filter, final FileFormater formater) {
		StringBuilder sb = new StringBuilder();

		sb.append(traverseFiles(files, filter, formater, true));
		sb.append(traverseFiles(files, filter, formater, false));

		return sb.toString();
	}

	private String traverseFiles(final List<FtpFile> files,
			final FileFilter filter, final FileFormater formater,
			boolean matchDirs) {
		StringBuilder sb = new StringBuilder();
		for (FtpFile file : files) {
			if (file == null) {
				continue;
			}

			if (filter == null || filter.accept(file)) {
				if (file.isDirectory() == matchDirs) {
					sb.append(formater.format(file));
				}
			}
		}

		return sb.toString();
	}

	public String listFiles(final ListArgument argument,
			final FileSystemView fileSystemView, final FileFormater formater)
			throws IOException {

		StringBuilder sb = new StringBuilder();

		// get all the file objects
		List<FtpFile> files = listFiles(fileSystemView, argument.getFile());
		if (files != null) {
			FileFilter filter = null;
			if (!argument.hasOption('a')) {
				filter = new VisibleFileFilter();
			}
			if (argument.getPattern() != null) {
				filter = new RegexFileFilter(argument.getPattern(), filter);
			}

			sb.append(traverseFiles(files, filter, formater));
		}

		return sb.toString();
	}

	/**
	 * Get the file list. Files will be listed in alphabetlical order.
	 */
	private List<FtpFile> listFiles(FileSystemView fileSystemView, String file) {
		List<FtpFile> files = null;
		try {
			FtpFile virtualFile = fileSystemView.getFile(file);
			if (virtualFile.isFile()) {
				files = new ArrayList<FtpFile>();
				files.add(virtualFile);
			} else {
				files = virtualFile.listFiles();
			}
		} catch (FTPServerException ex) {
		}
		return files;
	}
}
